1. Which environmental impact is caused by both refining oil and refining natural gas?
A. landslides
B. sinkholes
C. air pollution
D. marine habitat destruction
2. Which of the following is the cleanest-burning fossil fuel?
A. coal
B. natural gas
C. crude oil
D. carbon
3. Which statement accurately compares the environmental impact of underground mining and hydraulic fracturing?(1 point)
A. Both can impact marine wildlife.
B. Both can cause earthquakes.
C. Both can cause sinkholes.
D. Both involve digging deep into the earth.